Like most gay bathhouses, River Street Club is a private club to which a membership is required. You can buy a one-day pass, or a membership good for six months. The six-month deal costs $40, versus $12 for a one-day pass, so if you're planning to come back a few times, buy the pass. Additionally, there are rates for visiting, starting around $13 on weekdays ($16 on weekends) for a basic locker and about twice that for deluxe rooms.
River Street Club isn't a big facility, but it is clean and well-kept, with a gym, four-man sauna, steam room, six-man hot tub, and showers. The crowd tends toward the over-30 side, but this is a part of New York with numerous colleges and universities, and it's not uncommon to see students in here, especially on late evenings. It's an easy drive here from Lark Street in Albany, which contains the bulk of the area's gay bars.

